Bryant 580F K. Outdoor Air Humidity Sensor, L. Indoor Air Humidity Sensor

The user can read the value of the sensor using the Read mode, described in the EconoMi$er+ Controller section.

Mount the return air temperature sensor on the EconoMi$er+, through pre-punched holes. See Fig. 27.

The return air temperature (RAT) sensor is provided with a 2-wire, 42-in. long wiring harness with a 2-pin connector. The plug is installed on pins 5 and 6 on J3 of the EconoMi$er+ controller. The pins are labeled with a ground symbol and RAT on the EconoMi$er+ controller. See Fig. 22. The red wire of the harness is connected to pin 5 (ground). The black wire of the harness is connected to pin 6 (RAT). The wiring harness should be routed from the EconoMi$er+ controller to the sensor. The controller compares the temper- atures of the two airstreams, chooses the best one, and mod- ulates the EconoMi$er+ actuator accordingly.

This 10K thermistor is used to measure the return air temperature vs. resistance curve, per Table 5. The range of temperature measurement is between 0° and 158 F. See Table 6 for resolution.

K. Outdoor Air Humidity Sensor

The EconoMi$er+ controller accepts input from the accessory outdoor air humidity sensor in addition to the outdoor air tem- perature sensor shipped with the EconoMi$er+. By using both sensors, the total enthalpy of the outside air is calculated.

Mount the outdoor-air humidity sensor in to the EconoMi$er+, through the pre-punched holes. See Fig. 28. The outdoor-air humidity sensor is provided with a 2-wire, 42-in. wiring harness with a 2-pin connector. The plug is installed on pins 11 and 12 on J3 of the EconoMi$er+ con- troller. The pins are labeled ORH and VREF on the EconoMi$er+ controller. See Fig. 22. The orange wire of the harness is connected to pin 11 (ORH). The blue wire of the harness is connected to pin 12 (VREF). The wiring harness should be routed from the EconoMi$er+ controller to the sen- sor location.

The outdoor enthalpy changeover curve is set at the EconoMi$er+ controller. The factory default is curve “A.” See Fig. 29. See Fig. 30 for Sensor Curve vs. Humidity.

L. Indoor Air Humidity Sensor

For differential enthalpy sensing, the EconoMi$er+ control- ler uses the standard outdoor air temperature sensor, the outdoor air humidity sensor, and the optional indoor air humidity sensor, an optional return air temperature sensor (RAT). The indoor-air humidity sensor is provided with a 2-wire, 42-in. wiring harness with a 2-pin connector. The plug is installed on pins 8 and 9 on J3 of the EconoMi$er+ controller. The pins are labeled IRH and VREF on the EconoMi$er+ controller. See Fig. 22. The orange wire of the harness is connected to pin 8 (IRH). The blue wire of the har- ness is connected to pin 9 (VREF). The wiring harness should be extended with wires and wire nuts and routed from the EconoMi$er+ controller to the sensor location. The EconoMi$er+ controller compares the outdoor air enthalpy to the return air enthalpy to determine EconoMi$er+ use.

The controller selects the lower enthalpy air (return or out- door) for cooling. For example, when the outdoor air has a lower enthalpy than the return air, the EconoMi$er+ control- ler opens the damper to bring in outdoor air for free cooling.

Mount the return-air humidity sensor in the return-air duct. See Fig. 31.

The outdoor enthalpy changeover curve is set with at the EconoMi$er+ controller. The selectable curves are A, B, C, and D. The factory default is curve “A.” See Fig. 29. See Fig. 30 for Sensor Curve vs. Humidity.

CO2 SENSOR MAX RANGE SETTING

	6000
(ppm)	5000
CONFIGURATION	4000						800 ppm
	3000						900 ppm
							1000 ppm
	2000						1100 ppm
RANGE	1000
	0
	2	3	4	5	6	7	8
	DAMPER VOLTAGE FOR MAX VENTILATION RATE

Fig. 26 — Indoor Air Quality Voltage Setting

ECONOMI$ER+ CONTROLLER

HOOD

ACTUATOR

RETURN AIR

TEMP SENSOR

(HIDDEN)

GROMMET

CURB

INDOOR AIR

HUMIDITY SENSOR

VERTICAL ECONOMI$ER+ (3 TO 12 1/2 TON UNITS)

(SIDE VIEW)

Fig. 27 — Return Air Temperature Sensor

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